999 resultados para 112-683
Resumo:
Metallic catcher foils have been investigated on their thermal release capabilities for future superheavy element studies. These catcher materials shall serve as connection between production and chemical investigation of superheavy elements (SHE) at vacuum conditions. The diffusion constants and activation energies of diffusion have been extrapolated for various catcher materials using an atomic volume based model. Release rates can now be estimated for predefined experimental conditions using the determined diffusion values. The potential release behavior of the volatile SHE Cn (E112), E113, Fl (E114), E115, and Lv (E116) from polycrystalline, metallic foils of Ni, Y, Zr, Nb, Mo, Hf, Ta, and W is predicted. Example calculations showed that Zr is the best suited material in terms of on-line release efficiency and long-term operation stability. If higher temperatures up to 2773 K are applicable, tungsten is suggested to be the material of choice for such experiments.
Resumo:
User created content (UCC) has often been celebrated as a grassroots cultural revolution that as a genuine expression of creativity, localism and non-commercialism can arguably also cater for a sustainable culturally diverse environment. The present article puts these claims under scrutiny and in a more differentiated manner seeks to identify the value of UCC within digital game environments considering the constraints upon players and upon creative play that these impose. The article subsequently tests whether UCC in its dynamic sense of a creative and communicative process can be seen as a channel for the promotion of cultural diversity and if so, what the State should (and could) do about this.
Resumo:
Die Foliierung geht nur bis Bl. 552; zusätzlich gibt es die Blätter 229a, 319a, 488a und 508a; das Blatt 373 wurde bei der Foliierung übersprungen.
